SOLVED by:
startup.m (default MATLAB folder):
% SOLVE problem with upside down image by plot(1,1)
% see https://www.mathworks.com/matlabcentral/answers/445265-upside-down-display-of-graph
% more https://www.mathworks.com/matlabcentral/answers/349140-renderer-painters-vs-opengl
set(0, 'DefaultFigureRenderer', 'painters');